Presence of a drifting algal bed in the Mar Piccolo basin,Taranto (Ionian Sea,Southern Italy)

A survey is reported of the drifting algal community in Mar Piccolo, a polluted basin subject to sewage outlets. The key role was played by a few key species, mainly floridean red algae.     

REPRODUCTIVE DEVELOPMENT OF THE PARASITIC RED ALGA GARDNERIELLA TUBERIFERA (SOLIERIACEAE,GIGARTINALES)1

Examination of the reproductive morphology of the adelphoparasitic red alga Gardneriella tuberifera Kylin reveals that this monotypic genus is correctly placed in the family Solieriaceae (Gigartinales), to which its host Agardhiella gaudichaudii (Montagne) Silva et Papenfuss also belongs. Gardneriella is multiaxial, nonprocarpic and has an inwardly directed, three-celled carpogonial branch. The large, reniform uninucleate auxiliary cell is distinct prior to and after fertilization. It is diploidized by an unbranched, multicellular connecting filament which lacks pit connections. One or two connecting filaments arise from each fertilized carpogonium. From the diploidized auxiliary cell, the gonimoblast initial is cut off obliquely toward the interior of the thallus. The cells of the gonimoblast fuse with adjacent unpigmented vegetative cells of Gardneriella and pigmented cells of the host. These cells become incorporated into the developing cystocarp and, from those of Gardneriella, additional short chains of gonimoblast cells arise. The mature cystocarp is placentate, radiately lobed, and lacks a surrounding involucre. Carposporangia are borne in short chains and the unpigmented carpospores are released upon the dissolution of outer vegetative cells. No ostiole is present. Gardneriella appears to be most closely related to the placentate solieriacean genera Agardhiella, Sarcodiotheca, and Meristiella and therefore this genus should be placed in the tribe recently erected for these taxa, the Agardhielleae.     

Characterization of the edible red alga Meristotheca papulosa (Solieriaceae, Gigartinales) from Japan

The vegetative and reproductive morphology of the edible red alga Meristotheca papulosa (Montagne) J. Agardh (Solieriaceae) was reexamined based on material collected from various localities in Japan. Although the habit of the blades is variable according to the length and width of the axes, the frequency of branching and the abundance of proliferations, rbcL sequence analyses indicate their conspecificity. M. papulosa displays four distinctive reproductive features (presence of an auxiliary cell complex, occurrence of cystocarps on marginal proliferations and the blade surface (although very rare) in addition to the margins of axes, frequent production of spinose outgrowths on the pericarp and tetrasporangial initials typically basally attached to their parental cells) that have not been reported for M. papulosa from other areas. Although these features might warrant recognition of the Japanese entity as a separate species, a better understanding of their possible taxonomic value requires comparisons with M. papulosa from other geographic regions, including the type locality.     

FINE CHEMICAL STRUCTURE OF CARRAGEENAN FROM THE COMMERCIALLY CULTIVATED KAPPAPHYCUS STRIATUM (SACOL VARIETY) (SOLIERIACEAE,GIGARTINALES, RHODOPHYTA)1

The polysaccharide extracted from Kappaphycus striatum (Schmitz) Doty (sacol variety), a recently farmed eucheumoid seaweed, was characterized by Fourier transform infrared and NMR spectroscopy. The extract is composed mainly of 3‐linked β‐d ‐galactopyranosyl‐4‐sulfate residues alternating with 4‐linked 3,6‐anhydro‐α‐d ‐galactopyranosyl residues (κ‐carrageenan). Minor components include 3,6‐anhydrogalactopyranosyl‐2‐sulfate residues (ι‐carrageenan) and 6‐O‐methylgalactopyranosyl‐4‐sulfate residues (methylated carrageenan). The substitution pattern of carrageenan in the tribe Eucheumatoideae and the family Solieriaceae is revisited in terms of chemotaxonomic affiliation.     

Taxonomic features of the red alga Meristotheca coacta (Solieriaceae, Gigartinales)

Vegetative and reproductive structures of the little‐known red alga, Meristotheca coacta Okamura (Solieriaceae, Gigartinales) were described on the basis of specimens collected from three localities in southern Japan, including an island close to the lectotype locality. Meristotheca coacta was shown to be a strongly supported monophyletic clade in our rbcL analyses. The taxonomic features of this species were reassessed. This species is characterized as follows: (i) the thalli consist of relatively thick (300–1400 μm from the uppermost to basal regions), elastic and rose‐red blades; (ii) the blades are irregularly lobed and branched into variously shaped segments with undulate and crispate margins; (iii) tetrasporangial initials are laterally attached to their parental cells and the lateral pit‐connections remain in mature tetrasporangia; (iv) gametophytes are dioecious; (v) carpogonial branches are three‐celled (occasionally two‐ or four‐celled); (vi) a darkly staining auxiliary cell complex is present and recognizable prior to diploidization; and (vii) cystocarps are produced along (or near) the margins of the blades and on the marginal proliferations and lack spinous outgrowths.     

TAXONOMY OF THE FLATTENED SOLIERIACEAE (RHODOPHYTA) IN BRAZIL: AGARDHIELLA AND MERISTIELLA1

Taxonomic studies of an extensive collection of flattened members of the Solieriaceae considered by many authors to be species of Agardhiella, Eucheuma, Meristotheca, and Meristiella lead us to conclude that they represent only two genera in Brazil: Agardhiella, including A. ramosissima (Harvey) Kylin and A. floridana (Kylin) Gabrielson ex Guimarães et Oliveira, and Meristiella, with only one species, M. gelidium (J. Agardh) Cheney et Gabrielson. Accordingly, we propose that 1) Meristotheca gigartinoides Joly et Ugadim be synonymized with Agardhiella floridana, and 2) Meristiella echinocarpa (Areschoug) Cheney et Gabrielson and M. schrammii (P. et H. Crouan) Cheney et Gabrielson be synonymized with Meristiella gelidium.     

New red alga Meristotheca imbricata (Solieriaceae, Gigartinales) from Japan

A new red alga Meristotheca imbricata Faye et Masuda (Solieriaceae, Gigartinales) was described on the basis of specimens collected from southern Japan. Although this species might have been for a long time included in the concept of M. coacta Okamura, until recently a very poorly known alga, it is distinguished from the latter by the following features: (i) each thallus consists of one primary blade and several secondary blades, the latter arising from the apical or subapical portion of terminal segments of the primary blade; (ii) the individual blades are repeatedly dichotomously divided into linear segments of which margins are neither undulate nor crispate, and are fleshy, imbricate, frequently anastomosing and often acervate; (iii) each tetrasporangial initial is attached by a basal pit-connection to the parental cell, and the position of the pit-connection changes from basal to lateral by inward growth of the tetrasporangium; and (iv) the carpogonial branches sometimes have a one-celled sterile lateral.     

CARRAGEENANS FROM AUSTRALIAN REPRESENTATIVES OF THE FAMILY CYSTOCLONIACEAE (GIGARTINALES, RHODOPHYTA), WITH DESCRIPTION OF CALLIBLEPHARIS CELATOSPORA SP. NOV., AND TRANSFER OF AUSTROCLONIUM TO THE FAMILY ARESCHOUGIACEAE

Ten Australian representatives from seven of the 10 genera presently constituting the family Cystocloniaceae have been analyzed for their cell-wall galactans. Included in our survey are the monotypic Australian-endemic genera Austroclonium , Gloiophyllis , Erythronaema , and Stictosporum , one species of Craspedocarpus , three species of Rhodophyllis , and two species of Calliblepharis . As one of the species of the latter genus is endemic to Western Australia and presently undescribed, we illustrate its habit and anatomical features in formally proposing to name it Calliblepharis celatospora Kraft, sp. nov. All the species surveyed essentially produce typical iota (ι)-carrageenans, with the exception of Austroclonium . The sulfated galactans from Austroclonium predominantly contain the repeating units of ι-, alpha (α)-, and 6'-O-methylated ι- and α-carrageenans; whether these exist as discrete polysaccharides or a complex hybrid structure was not resolved. Thus, Austroclonium carrageenans resemble the polysaccharides from Rhabdonia , Areschougia , and Erythroclonium . Although these latter three genera are currently included in the large gigartinalean family Solieriaceae, all produce significantly different carrageenans from Solieria itself and related genera such as Eucheuma , Kappaphycus , Betaphycus , Sarcodiotheca , Agardhiella , Sarconema , and Callophycus . In consideration of these findings, as well as of significant anatomical similarities, we provisionally recommend reestablishment of the family Rhabdoniaceae Kylin (as the family Areschougiaceae J. Agardh) for Rhabdonia , Areschougia , Erythroclonium , and Austroclonium.     

THE ATLANTIC SPECIES OF SOLIERIA (GIGARTINALES,RHODOPHYTA): THEIR MORPHOLOGY,DISTRIBUTION AND AFFINITIES1

Solieria chordalis (C. Agardh) J. Agardh and S. tenera (J. Agardh) Wynne et Taylor exhibit multiaxial growth from a cluster of four to eight obconical apical cells. A single periaxial cell is cut off from each axial cell and successive periaxial cells are rotated 120° in a zig-zag pattern along each axial filament. Periaxial cells produce branched, laterally diverging filaments which form the cortex. The medulla is composed of axial cells, elongate cells of lateral filaments, stretched interconnecting cells, and secondary rhizoids. The two species are nonprocarpic. Carpogonial branches are 3-celled, inwardly directed, with a reflexed trichogyne. The auxiliary cell together with associated darkly-staining inner cortical cells form an association, the auxiliary cell complex, that is recognizable prior to diploidization. A single, unbranched, non-septate connecting filament issues from the fertilized carpogonium and fuses with the inner, lateral side of an auxiliary cell. Production of an involucre from surrounding vegetative cells is stimulated and a gonimoblast initial is cut off toward the interior of the thallus which divides to form a compact cluster of gonimoblast cells. A fusion cell is produced through fusion of inner gonimoblast cells with the auxiliary cell that, in turn, fuses progressively with cells of the lateral file bearing the auxiliary cell. Mature cystocarps have terminal carposporangia cut off from gonimoblast cells at the periphery of the fusion cell and are surrounded by an involucre with a distinct ostiole. Tetrasporangia are cut off laterally from surface cortical cells which then cut off one or two additional derivatives toward the outside. A lectotype is designated for Solieria chordalis, but the lectotypification of S. tenera is questioned. We conclude that Solieria is closely related to Rhabdonia and place the Rhabdoniaceae in synonomy with the Solieriaceae.